Magali Brunet | Centre National de la Recherche Scientifique / French National Centre for Scientific Research (original) (raw)

Papers by Magali Brunet

Research paper thumbnail of Implantable planar rf microcoils for NMR microspectroscopy

Sensors and Actuators A-physical, 2002

Research paper thumbnail of Microfabricated coupled inductors for DC-DC converters for microprocessor power delivery

Research paper thumbnail of Electrochemical process for the lamination of magnetic cores in thin-film magnetic components

IEEE/ASME Journal of Microelectromechanical Systems, 2006

Page 1. 94 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 15, NO. 1, FEBRUARY 2006 Electrochemic... more Page 1. 94 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 15, NO. 1, FEBRUARY 2006 Electrochemical Process for the Lamination of Magnetic Cores in Thin-Film Magnetic Components Magali Brunet, Terence ...

Research paper thumbnail of Microfabricated coupled inductors for integrated power converters

Journal of Magnetism and Magnetic Materials, 2005

Research paper thumbnail of Design study and fabrication techniques for high power density microtransformers

This paper presents an investigation into the power density and efficiency achievable from microt... more This paper presents an investigation into the power density and efficiency achievable from microtransformers suitable for integration on silicon. Results from the design study indicate that high aspect ratio conductors and laminated cores are required to achieve high power density. Fabrication techniques, using thick photoresist, which can be used to achieve high aspect ratios, have been developed and results are presented. Initial test results for the inductance and resistance of the coils are also presented

Research paper thumbnail of Pulse reverse plating for integrated magnetics on Si

Journal of Magnetism and Magnetic Materials, 2005

Research paper thumbnail of Thick photoresist development for the fabrication of high aspect ratio magnetic coils

Journal of Micromechanics and Microengineering, 2002

... Magali Brunet1, Terence O'Donnell1, Joe O'B... more ... Magali Brunet1, Terence O'Donnell1, Joe O'Brien2, Paul McCloskey1 and Seán Cian ´O Mathuna2 ... Abstract This paper reports the fabrication of coils for micro-magnetic devices on silicon using thick photoresists commonly used in the manufacture of microelectromechanical ...

Research paper thumbnail of Thin film micro-transformers for future power conversion

This paper presents an investigation into the use of micro-fabricated transformers for future pow... more This paper presents an investigation into the use of micro-fabricated transformers for future power conversion in the 5-10 MHz frequency range. The structure of the micro-transformers is described and an analytical model is used to optimize the transformer for maximum efficiency. The optimized devices are based on improved fabrication processes which give 80 μm thick copper conductors and a two layer laminated magnetic core. The optimization suggests that an efficiency of 82% at an output power of 3.5 W can be achieved. Initial small signal results are presented for micro-transformers fabricated using the improved processes. The estimated efficiency of the fabricated microtransformer based on these results is 78%.

Research paper thumbnail of High-frequency micro-machined power inductors

Journal of Magnetism and Magnetic Materials, 2005

Research paper thumbnail of Electrical performance of microtransformers for DC-DC converter applications

IEEE Transactions on Magnetics, 2002

... four-point probe method and the permeability was determined from measurement of inductance on... more ... four-point probe method and the permeability was determined from measurement of inductance on ... The measurements of the transformer in a dc–dc converter show an output ... Kazimierczuck, and A. Massarini, “High-frequency behavior of laminated iron-core inductors for filtering ...

Research paper thumbnail of Deep trench MOSFET structures study for a 1200 Volts application

In this work we studied some possible high voltage MOSFETs structures that can replace the IGBT i... more In this work we studied some possible high voltage MOSFETs structures that can replace the IGBT in the railway traction converters. In this purpose, some high voltage power MOS structures are presented and theoretically compared using 2D simulations. Simulations results show that the DT-UMOSFET should be a good challenger to the 1200 Volts IGBT. Moreover, the influence of various parameters, like trench width, trench verticality or boron dose, on DT-UMOSFET static performances is shown.

Research paper thumbnail of Performance of 3D capacitors integrated on silicon for DC-DC converter applications

The integration of passive components on silicon for future DC-DC converters applications is stil... more The integration of passive components on silicon for future DC-DC converters applications is still a challenging area of research. This paper focuses on integrated 3D capacitors with high capacitance density fabricated with microfabrication techniques on silicon and in particular DRIE. The fabricated prototypes were characterised: a capacitance density between 29 and 46 nF/mm2 was demonstrated up to 800 kHz. An improvement is presented on the equivalent series resistance (ESR), which impedes currently on the component utilisation at higher frequencies.

Research paper thumbnail of Factorial experimental design applied to DRIE for optimised process in power electronics applications requiring high-aspect ratio trenches

Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, 2009

A reliable factorial experimental design was applied to DRIE for specifically producing high-aspe... more A reliable factorial experimental design was applied to DRIE for specifically producing high-aspect ratio trenches. These trenches are to be used in power electronics applications such as active devices: deep trench superjunction MOSFET (DT-SJMOSFET) and passive devices: 3D integrated capacitors. Analytical expressions of the silicon etch rate, the verticality of the profiles, the selectivity of the mask and the critical loss dimension were extracted versus the process parameters. The influence of oxygen in the passivation plasma step was observed and explained. Finally, the analytical expressions were applied to the devices objectives. A perfectly vertical trench 100-μm deep was obtained for DT-SJMOSFET. Optimum conditions for reaching high-aspect ratio structures were determined in the case of high-density 3D capacitors.

Research paper thumbnail of Implantable planar rf microcoils for NMR microspectroscopy

Sensors and Actuators A-physical, 2002

Research paper thumbnail of Microfabricated coupled inductors for DC-DC converters for microprocessor power delivery

Research paper thumbnail of Electrochemical process for the lamination of magnetic cores in thin-film magnetic components

IEEE/ASME Journal of Microelectromechanical Systems, 2006

Page 1. 94 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 15, NO. 1, FEBRUARY 2006 Electrochemic... more Page 1. 94 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 15, NO. 1, FEBRUARY 2006 Electrochemical Process for the Lamination of Magnetic Cores in Thin-Film Magnetic Components Magali Brunet, Terence ...

Research paper thumbnail of Microfabricated coupled inductors for integrated power converters

Journal of Magnetism and Magnetic Materials, 2005

Research paper thumbnail of Design study and fabrication techniques for high power density microtransformers

This paper presents an investigation into the power density and efficiency achievable from microt... more This paper presents an investigation into the power density and efficiency achievable from microtransformers suitable for integration on silicon. Results from the design study indicate that high aspect ratio conductors and laminated cores are required to achieve high power density. Fabrication techniques, using thick photoresist, which can be used to achieve high aspect ratios, have been developed and results are presented. Initial test results for the inductance and resistance of the coils are also presented

Research paper thumbnail of Pulse reverse plating for integrated magnetics on Si

Journal of Magnetism and Magnetic Materials, 2005

Research paper thumbnail of Thick photoresist development for the fabrication of high aspect ratio magnetic coils

Journal of Micromechanics and Microengineering, 2002

... Magali Brunet1, Terence O'Donnell1, Joe O'B... more ... Magali Brunet1, Terence O'Donnell1, Joe O'Brien2, Paul McCloskey1 and Seán Cian ´O Mathuna2 ... Abstract This paper reports the fabrication of coils for micro-magnetic devices on silicon using thick photoresists commonly used in the manufacture of microelectromechanical ...

Research paper thumbnail of Thin film micro-transformers for future power conversion

This paper presents an investigation into the use of micro-fabricated transformers for future pow... more This paper presents an investigation into the use of micro-fabricated transformers for future power conversion in the 5-10 MHz frequency range. The structure of the micro-transformers is described and an analytical model is used to optimize the transformer for maximum efficiency. The optimized devices are based on improved fabrication processes which give 80 μm thick copper conductors and a two layer laminated magnetic core. The optimization suggests that an efficiency of 82% at an output power of 3.5 W can be achieved. Initial small signal results are presented for micro-transformers fabricated using the improved processes. The estimated efficiency of the fabricated microtransformer based on these results is 78%.

Research paper thumbnail of High-frequency micro-machined power inductors

Journal of Magnetism and Magnetic Materials, 2005

Research paper thumbnail of Electrical performance of microtransformers for DC-DC converter applications

IEEE Transactions on Magnetics, 2002

... four-point probe method and the permeability was determined from measurement of inductance on... more ... four-point probe method and the permeability was determined from measurement of inductance on ... The measurements of the transformer in a dc–dc converter show an output ... Kazimierczuck, and A. Massarini, “High-frequency behavior of laminated iron-core inductors for filtering ...

Research paper thumbnail of Deep trench MOSFET structures study for a 1200 Volts application

In this work we studied some possible high voltage MOSFETs structures that can replace the IGBT i... more In this work we studied some possible high voltage MOSFETs structures that can replace the IGBT in the railway traction converters. In this purpose, some high voltage power MOS structures are presented and theoretically compared using 2D simulations. Simulations results show that the DT-UMOSFET should be a good challenger to the 1200 Volts IGBT. Moreover, the influence of various parameters, like trench width, trench verticality or boron dose, on DT-UMOSFET static performances is shown.

Research paper thumbnail of Performance of 3D capacitors integrated on silicon for DC-DC converter applications

The integration of passive components on silicon for future DC-DC converters applications is stil... more The integration of passive components on silicon for future DC-DC converters applications is still a challenging area of research. This paper focuses on integrated 3D capacitors with high capacitance density fabricated with microfabrication techniques on silicon and in particular DRIE. The fabricated prototypes were characterised: a capacitance density between 29 and 46 nF/mm2 was demonstrated up to 800 kHz. An improvement is presented on the equivalent series resistance (ESR), which impedes currently on the component utilisation at higher frequencies.

Research paper thumbnail of Factorial experimental design applied to DRIE for optimised process in power electronics applications requiring high-aspect ratio trenches

Microsystem Technologies-micro-and Nanosystems-information Storage and Processing Systems, 2009

A reliable factorial experimental design was applied to DRIE for specifically producing high-aspe... more A reliable factorial experimental design was applied to DRIE for specifically producing high-aspect ratio trenches. These trenches are to be used in power electronics applications such as active devices: deep trench superjunction MOSFET (DT-SJMOSFET) and passive devices: 3D integrated capacitors. Analytical expressions of the silicon etch rate, the verticality of the profiles, the selectivity of the mask and the critical loss dimension were extracted versus the process parameters. The influence of oxygen in the passivation plasma step was observed and explained. Finally, the analytical expressions were applied to the devices objectives. A perfectly vertical trench 100-μm deep was obtained for DT-SJMOSFET. Optimum conditions for reaching high-aspect ratio structures were determined in the case of high-density 3D capacitors.